A sheet conveying apparatus used in a sheet processing apparatus for processing sheets such as marketable securities is an apparatus for taking out and conveying the sheets one by one, performing authenticity discrimination or quality bill and disqualified bill discrimination of the sheets regarding a predetermined check area set on each sheet surface, and sorting them on the discrimination results. Therefore, the sheet processing apparatus, to stably ensure the check area and perform the sorting process such as the stacking process based on the check results, a meandering countermeasure for performing normal conveyance is important.
Conventionally, as such a meandering countermeasure, for example, in the case of conveyance using a flat belt, (1) installation of a crowning roller (a crown-shaped roller) (for example, refer to Patent Document 1) and (2) installation of a flange roller are known. Patent Document 1: Japanese Patent Application 2006-1670 (FIGS. 3 and 4 on pages 5 and 6)
However, in the sheet processing apparatus stated in Patent Document 1, when the material of the flat belt is hard, in the countermeasure of installation of the crowning roller, the belt does not get to fit the roller and the effect is low. Further, when the flange roller is installed for the conventional belt at the sheet conveying position, only a flange roller having a flange height in correspondence to the belt thickness can be installed and a problem arises that the belt runs over the flange.
The present invention was developed to solve the aforementioned problem and is intended to provide a sheet conveying apparatus capable of prevent meandering of the belt by using a flange roller with a flange height higher than the thickness of the belt in the folding-back portion of the conveying roller in the neighborhood of the discontinuous portions of belt conveyance such as the entrance portion of sheets and the exit portion of sheets.